llvm/test/Analysis/BasicAA/phi-speculation.ll

target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"

; RUN: opt < %s -basic-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s

; ptr_phi and ptr2_phi do not alias.
; CHECK: test_noalias_1
; CHECK: NoAlias: i32* %ptr2_phi, i32* %ptr_phi
; CHECK: NoAlias: i32* %ptr2_inc, i32* %ptr_inc
define i32 @test_noalias_1(i32* %ptr2, i32 %count, i32* %coeff) {
entry:
  %ptr = getelementptr inbounds i32, i32* %ptr2, i64 1
  br label %while.body

while.body:
  %num = phi i32 [ %count, %entry ], [ %dec, %while.body ]
  %ptr_phi = phi i32* [ %ptr, %entry ], [ %ptr_inc, %while.body ]
  %ptr2_phi = phi i32* [ %ptr2, %entry ], [ %ptr2_inc, %while.body ]
  %result.09 = phi i32 [ 0 , %entry ], [ %add, %while.body ]
  %dec = add nsw i32 %num, -1
  %0 = load i32, i32* %ptr_phi, align 4
  store i32 %0, i32* %ptr2_phi, align 4
  %1 = load i32, i32* %coeff, align 4
  %2 = load i32, i32* %ptr_phi, align 4
  %mul = mul nsw i32 %1, %2
  %add = add nsw i32 %mul, %result.09
  %tobool = icmp eq i32 %dec, 0
  %ptr_inc = getelementptr inbounds i32, i32* %ptr_phi, i64 1
  %ptr2_inc = getelementptr inbounds i32, i32* %ptr2_phi, i64 1
  br i1 %tobool, label %the_exit, label %while.body

the_exit:
  ret i32 %add
}

; CHECK: test_noalias_2
; CHECK: NoAlias: i32* %ptr_outer_phi, i32* %ptr_outer_phi2
; CHECK: NoAlias: i32* %ptr2_inc_outer, i32* %ptr_inc_outer
; CHECK: NoAlias: i32* %ptr2_phi, i32* %ptr_phi
; CHECK: NoAlias: i32* %ptr2_inc, i32* %ptr_inc
define i32 @test_noalias_2(i32* %ptr2, i32 %count, i32* %coeff) {
entry:
  %ptr = getelementptr inbounds i32, i32* %ptr2, i64 1
  br label %outer.while.header

outer.while.header:
  %ptr_outer_phi = phi i32* [%ptr_inc_outer, %outer.while.backedge], [ %ptr, %entry]
  %ptr_outer_phi2 = phi i32* [%ptr2_inc_outer, %outer.while.backedge], [ %ptr2, %entry]
  %num.outer = phi i32 [ %count, %entry ], [ %dec.outer, %outer.while.backedge ]
  br label %while.body

while.body:
  %num = phi i32 [ %count, %outer.while.header ], [ %dec, %while.body ]
  %ptr_phi = phi i32* [ %ptr_outer_phi, %outer.while.header ], [ %ptr_inc, %while.body ]
  %ptr2_phi = phi i32* [ %ptr_outer_phi2, %outer.while.header ], [ %ptr2_inc, %while.body ]
  %result.09 = phi i32 [ 0 , %outer.while.header ], [ %add, %while.body ]
  %dec = add nsw i32 %num, -1
  %0 = load i32, i32* %ptr_phi, align 4
  store i32 %0, i32* %ptr2_phi, align 4
  %1 = load i32, i32* %coeff, align 4
  %2 = load i32, i32* %ptr_phi, align 4
  %mul = mul nsw i32 %1, %2
  %add = add nsw i32 %mul, %result.09
  %tobool = icmp eq i32 %dec, 0
  %ptr_inc = getelementptr inbounds i32, i32* %ptr_phi, i64 1
  %ptr2_inc = getelementptr inbounds i32, i32* %ptr2_phi, i64 1
  br i1 %tobool, label %outer.while.backedge, label %while.body

outer.while.backedge:
  %ptr_inc_outer = getelementptr inbounds i32, i32* %ptr_phi, i64 1
  %ptr2_inc_outer = getelementptr inbounds i32, i32* %ptr2_phi, i64 1
  %dec.outer = add nsw i32 %num.outer, -1
  %br.cond = icmp eq i32 %dec.outer, 0
  br i1 %br.cond, label %the_exit, label %outer.while.header

the_exit:
  ret i32 %add
}

; CHECK: test_noalias_3
; CHECK: MayAlias: i8* %ptr2_phi, i8* %ptr_phi
define i32 @test_noalias_3(i8* noalias %x, i8* noalias %y, i8* noalias %z,
                           i32 %count) {
entry:
  br label %while.body

while.body:
  %num = phi i32 [ %count, %entry ], [ %dec, %while.body ]
  %ptr_phi = phi i8* [ %x, %entry ], [ %z, %while.body ]
  %ptr2_phi = phi i8* [ %y, %entry ], [ %ptr_phi, %while.body ]
  %dec = add nsw i32 %num, -1
  %tobool = icmp eq i32 %dec, 0
  br i1 %tobool, label %the_exit, label %while.body

the_exit:
  ret i32 1
}

; CHECK-LABEL: test_different_stride_noalias
; CHECK: NoAlias: i16* %y.base, i8* %x.base
; CHECK: NoAlias: i16* %y, i8* %x
; CHECK: NoAlias: i16* %y.next, i8* %x.next
define void @test_different_stride_noalias(i1 %c, i8* noalias %x.base, i16* noalias %y.base) {
entry:
  br label %loop

loop:
  %x = phi i8* [ %x.base, %entry ], [ %x.next, %loop ]
  %y = phi i16* [ %y.base, %entry ], [ %y.next, %loop ]
  %x.next = getelementptr i8, i8* %x, i64 1
  %y.next = getelementptr i16, i16* %y, i64 1
  br i1 %c, label %loop, label %exit

exit:
  ret void
}

; CHECK-LABEL: test_no_loop_mustalias
; CHECK: MustAlias: i16* %z16, i8* %z8
define void @test_no_loop_mustalias(i1 %c, i8* noalias %x8, i8* noalias %y8) {
  br i1 %c, label %if, label %else

if:
  %x16 = bitcast i8* %x8 to i16*
  br label %end

else:
  %y16 = bitcast i8* %y8 to i16*
  br label %end

end:
  %z8 = phi i8* [ %x8, %if ], [ %y8, %else ]
  %z16 = phi i16* [ %x16, %if ], [ %y16, %else ]
  ret void
}

; CHECK-LABEL: test_same_stride_mustalias
; CHECK: MustAlias: i4* %y.base, i8* %x.base
; CHECK: MayAlias: i4* %y, i8* %x
; CHECK: MayAlias: i4* %y.next, i8* %x.next
; TODO: (x, y) could be MustAlias
define void @test_same_stride_mustalias(i1 %c, i8* noalias %x.base) {
entry:
  %y.base = bitcast i8* %x.base to i4*
  br label %loop

loop:
  %x = phi i8* [ %x.base, %entry ], [ %x.next, %loop ]
  %y = phi i4* [ %y.base, %entry ], [ %y.next, %loop ]
  %x.next = getelementptr i8, i8* %x, i64 1
  %y.next = getelementptr i4, i4* %y, i64 1
  br i1 %c, label %loop, label %exit

exit:
  ret void
}

; CHECK-LABEL: test_different_stride_mustalias
; CHECK: MustAlias: i16* %y.base, i8* %x.base
; CHECK: MayAlias: i16* %y, i8* %x
; CHECK: MayAlias: i16* %y.next, i8* %x.next
; Even though the base pointers MustAlias, the different strides don't preserve
; this property across iterations.
define void @test_different_stride_mustalias(i1 %c, i8* noalias %x.base) {
entry:
  %y.base = bitcast i8* %x.base to i16*
  br label %loop

loop:
  %x = phi i8* [ %x.base, %entry ], [ %x.next, %loop ]
  %y = phi i16* [ %y.base, %entry ], [ %y.next, %loop ]
  %x.next = getelementptr i8, i8* %x, i64 1
  %y.next = getelementptr i16, i16* %y, i64 1
  br i1 %c, label %loop, label %exit

exit:
  ret void
}